i used to own both consoles, to be honest the only way xbox live is superior is because of the croos chat feature, and even then psn is really not that far behind. I personally have never had any problems with trying to find people online to have matched with on Uncharted 2, MW1, or MW2
Finally you will find the community is alot friendlier, and in my opinion have a PS3 is much better.
it's the future of handheld
PS VITA = LIFE
The official Vita thread http://gamrconnect.vgchartz.com/thread.php?id=130023&page=1